A first-person account from a senior director on the National Security Council during the 2011 Tohoku earthquake and subsequent disaster at the Fukushima Daiichi Nuclear Plant in Japan.

Kan bows to the Japanese flag before a news conference in Tokyo on April 12, 2011. (j808armada / flickr)

My father was an engineer, and when I was a child, he told me the story of Prometheus, a famous Greek myth in which Zeus grows angry at Prometheus for giving humans the wisdom of fire, knowledge capable of bringing on disaster. As punishment, Zeus chains Prometheus to a rock, where an eagle pecks incessantly at his liver. Today, I cannot help but remember that story when I think about the development of nuclear technology, a modern-day incarnation of the wisdom of fire.

In college, I studied science and technology, and ever since, I have had a great admiration for the Pugwash conferences, a forum dedicated to the elimination of nuclear weapons (the group won the Nobel Peace Prize in 1993). That is because nuclear weapons, which have the power to kill large numbers of people indiscriminately, are fundamentally at odds with the purpose of science, which is to contribute to people's well-being. To put it another way: Nuclear weapons contradict the very nature of humanity. In fact, this concern was the major reason why I aspired to be a political leader.

Long before the accident at the Fukushima Daiichi nuclear power plant, I knew there were serious unresolved issues regarding the safety of nuclear power and the disposal of radioactive waste. I took the position that these issues could be overcome by technology. With adequate safeguards, nuclear power plants could be operated safely and utilized wisely. Especially in recent years, in order to prevent global warming, nuclear power has been an effective replacement to power plants that feed on fossil fuels and pollute the atmosphere. In fact, before Fukushima, Japan had a plan to expand its network of nuclear plants.

Then, while I was serving as prime minister, the Tohoku earthquake occurred at 2:46 PM on March 11, 2011. Immediately, all reactors in operation at Fukushima Daiichi were shut down; nuclear activity there came to a halt. An hour after the earthquake, I received a report from Tokyo Electric Power Company (TEPCO) stating that several power generators at the Fukushima site were experiencing a total loss of power. An hour after that, there was an accident that suspended the cooling function. The earthquake had toppled the steel towers supporting power transmission lines. Saltwater damage rendered the emergency diesel generators inoperable. All power sources had been lost.

I was fully aware that total power loss and the suspension of cooling functions could then cause a meltdown and lead to further serious accidents such as the destruction of the reactor and the release of radioactive materials into the atmosphere. We took every possible precaution, but our preparedness against total power loss proved insufficient. Over the next five days, Units 1, 2, and 3 melted down. Later, hydrogen explosions occurred inside the building of Units 1, 3, and 4. Fuel pools, used to store spent fuel, adjoin each reactor, and at one time, there was a possibility of the meltdown of this fuel pool, too. In the event of the meltdown of the fuel pools, a large amount of radioactive materials would have been discharged into the atmosphere, and if it continued, the evacuation of the entire metropolitan area, including Tokyo, might have been necessary.

If the reactors and spent fuel pools had gotten out of control, an enormous amount of radioactive material, possibly even several times more than the Chernobyl accident, would have been discharged into the atmosphere, impacting neighboring countries. To prevent this from happening was our responsibility as a nation. I was determined to fight to resolve the accident until the very end and at any cost, including the risk of my own life.

The invisible menace of radioactivity would have seized Tokyo. The city is our nation's political and economic nerve center. Some 30 million people live in the metropolitan area. The impact of evacuating them all would have been immense. The impact on not only political matters but also the economy and human lives would have been immeasurable.

Fortunately, thanks to the life-risking efforts by TEPCO personnel, Japan's Self-Defense Forces, and local fire and police departments, injecting water into the reactors and fuel pools prevented further meltdowns and brought the entire accident under control. A very bad situation was narrowly prevented from becoming an accident of catastrophic proportions.

This accident was a war with an invisible enemy. The worst case scenario would have brought serious harm to the nation of Japan as well as a considerable inconvenience to its neighbors.

I have thought very hard about the types of safety measures necessary to prevent any such disaster from happening again. However, when one weighs these measures against the tremendous risks, it is clear that no amount of precautions will make a country completely safe from nuclear energy. I have reached the conclusion, therefore, that the only option is to promote a society free of nuclear power. My administration, as a result, changed its policy to reduce Japan's dependency on nuclear power, and the current administration is basically following the same policy.

Furthermore, the final disposal of high-level radioactive waste, which needs to be isolated from humans for more than 100,000 years before decaying to a safe level, is a serious issue. Far into the future, it is possible that current nations or boundaries could look very different. Therefore, we need to address whether responsibility for final disposal should rest solely with each nation. Although the International Atomic Energy Agency (IAEA) currently states that the onus lies with each country, many nations, including Japan, do not have any clear solutions.

At the same time, this high-level radioactive waste problem presents a "generation ethics" issue: should we leave our burdens to future generations?

Despite the accident at Fukushima, plans abound for new nuclear power plants. Emerging nations such as China and India propose to meet their increased energy demands with new nuclear power. When it comes to nuclear weapons, the Nuclear Nonproliferation Treaty established clear rules. However, with regard to nuclear power, there are insufficient mandates when it comes to safety. In large part, so long as a country's nuclear program does not involve weapons production, its operation and control are considered to be the responsibility of that state alone. Likewise, the export of nuclear power plant technology is also often just a business issue, not one of international security.

At the current rate, by the year 2030, the world can anticipate at least 100 more nuclear power plants in addition to the 432 already in existence. With this expected increase, the problems of whether the safety of the world can be secured without establishing an international institution to guarantee protection against severe accidents and the safety of final disposal of high-level radioactive waste weigh heavy on my mind.

International rules regarding nuclear power plants should be discussed not only at the international organizational level on nuclear power such as the IAEA but also at the level of the United Nations.

While the Fukushima accident was caused by a total loss of power as a result of the earthquake and tsunami, other means -- such as terrorism, civil war, or war against other countries -- could bring about the same result. Taking advantage of the lessons we learned from the Fukushima nuclear power plant accident, Japan should become a model country that is able to supply all its energy needs without depending upon nuclear power or fossil fuels.

In conclusion, I would like to suggest that every nation seriously consider a new framework for international rules regarding the safety of nuclear power plans and the disposal of high-level of radioactive waste. The costs of not doing so could ultimately be far too much to bear.